The first I heard of Wix was a few months ago when a local news site deployed their new design. The page would be completely blank for 10-15 seconds while it made hundreds of requests for useless little React turdlets. As far as I can tell, they "fixed" it by moving away from Wix.
If that's normal for a Wix site, then I would say no, nobody involved on either side of the transaction is a web developer except in the most pejorative sense of the term.